Extreme pressure lubricant



Patented Dec.- 15,1942

zsmioi mssun'n LUBRICANT Bradshaw r. amends, llaytowm'lex 'asaignor toStandard Oil Development Company, a corpo- I ration of Delaware NoDrawing. Application September 14, 1940,

. Serial No. 358,859

'6 Claims. (01. 252-48) This invention deals with the production and useof sulfur-containing compositions suitable for lubrication of movingparts especially when under severe conditions such as those encounteredwith heavy loads as well as those usually involved in hypoid gears andsimilar equipment.

. In the acid treatment of cracked naphthas and similar operations, asludge is formed which separates as a bottomlayer, and this is drawn offand generally possesses little commercial value. In the Showalter andWiggen application, Serial No.

solvent such as secondary amyl alcohol, isopropyl alcohol, etc., for aperiod of 4-12 hours. By such 293,050 flied on September 1, 1939, aprocess has been described for preparing oily products from thesesludges suitable as synthetic drying oils and as raw materials for otheruses. In short, the process involved consists of hydrolyzing the sludge,preferably naphtha sludge, with steam or hot water so as to recover aweak sulfuric acid and an oily layer which is formed as a result of thechemical reactions taking place during the hydrolysis operation. Thisoily layer is a viscous material which may be treated with propane orsimilar precipitant to precipitate out tarry constituents, coke, etc.,and the unprecipitated oil free of these asphaltic impurities isdistilled to remove the propane (or other precipitant) and furtherdistilled to give an overhead oil which is employed as the sourcematerial in the present invention. This oil will hereafter be designatedas hydrolyzed sludge oil.

A purpose of the present invention is to convert this hydrolyzed sludgeoil into a more useful and suitable material for the lubricationindustry.

' A further object is to produce from said oil a substantiallynon-volatile highly potent and cheap extreme pressure lubricant which iscomparable to and in many respects superior to other extreme pressurelubricating materials prepared from much more expensive raw materials.

Due to the highly unsaturated nature of the oil, it might be expectedthat sulfurization would produce a cokey, insoluble mass or a productwhich would have drying properties making the material unsuitable forlubricating purposes.

Contrary to these expectations, however, by suitable control of thereaction conditions, it has been possible to obtain high yields ofexcellent extreme pressure lubricant base from this raw material.

One method for producing such a base consists in chlorinating thehydrolyzed sludge oil or its distillates in presence of a solvent suchas carbon tetrachloride and at temperatures in the neighborhood of F.,more or less, until the oil has absorbed about -30% by weight ofchlorine.

This chlorinatedproduct is then reacted with a reactive sulfur compoundsuch as n-butyl mercaptide, sodium polysulflde, sodium hydrosulflde, ormixtures thereof by refluxing in presence of a treatment, sodiumchloride or equivalent material is precipitated out of the reactionmixture and may be filtered off, leaving the desired sulfurcontainingbase which may be recovered by ordinary or vacuum distillation. Toobtain a pure product, it is generally desirable to wash this oilysulfur-containing base with alkali in benzene or similar solventsolution. By controlling the amount of reactive sulfur compound, it ispossible to obtain a product which contains a major proportion or aminor proportion of chlorine or even a material substantially free ofchlorine or equivalent halogen. Such a base thus prepared generallycontains over 2% sulfur and, when added to a lubricating oil in aconcentration of to 20%,

more or less, produces an extreme pressure lubricant having exceptionalproperties and capable of passing corrosion, neutralization and similar4 critical tests.

Another method for producing a highly suitable extreme pressure base isto heat the hydrolyzed sludge oil with elementary sulfur (2-20% byweight) for to 4 hours at 200-400 F. Con-1 trary to what might beexpected, an unusually clear, viscous, reddish, sulfurized oil isobtained containing sulfur in the neighborhood of 2-10% and perfectlysoluble in paraflinic and other mineral lubricating oils. Such an oilpossesses not only load carrying properties but also corrosioninhibiting and antioxidant properties and also passes the rigorous testsimposed upon lubricants of this character.

The invention can be more readily understood by the following exampleswhich, however, are not intended to limit the invention in any manner:

Example I.-A sample of hydrolyzed sludge oil obtained from'treatingcracked naphtha with strong sulfuric acid, and processing according tothemethod described above, was mixed with an equivalent amount of carbontetrachloride, and chlorine was bubbled through the mixture at 0 F.until the oil had adsorbed 20% by weight of chlorine. A gm. sample ofthis chlorinated oil (containing about 1.21% sulfur) was then mixed with100 gms. of sodium n-buty1 mercaptide dissolved in 1 liter of secondaryamyl alcohol and the resultant mixture was refluxed for about 8 hours.After filtering pfl the salt, the sulfurized reaction product wassegregated from the alcohol and the unreacted constituents by vacuumdistillation. This product contained 9.15% sulfur after having beencaustic wash and water washed in benzene solution.

The sulfurlzed product thus formed was blended in concentrations of 0.5and 3% in a phenol extracted and dewaxed Coastal lubricating oil andinspections were made on the resulting blends with the followingresults:

Bulfurized oil added Blank, 0.5% 3% Viscosity at 100 F.,

S. U. S 1170 1146 1025 Viscosity at 210 F.,

8.U.S 84.7 84.5 80.2 Viscosity index 70 72 73 Pour point, "F 0 0 l0 Armyspecification emulsion test Trace Trace Pass Oxidation rate (oxygenabsorpxtlion cc. per 15 min. tervals at 250 0.)....'. 2o, 27, so, 29 18,19,17, 17 19,15, 15, 1a Viscosity at 210 F. after oxidation in Indianatest 99 106 99 Sulfur, per cent 0. 2 0. 24 0. 5 Corrosion PassNeutralization number. 0.02 0. 02 0. 03 Color, Tag. Robinson. 8% 0+ 7%Color-hold 16 hrs. at 250 F. Tag. Robinson...... 5% 4 2% From the abovedata, it can be readily seen that the sulfurized oil base does notdetrimentally affect the viscosity characteristics, and in fact, inconcentrations of 25%, distinctly lowers the pour point of the oil.Furthermore, the base exhibits antioxidant properties and yet does notprevent the blend from passing corrosion, neutralization and othertests.

Example II.-A sample of hydrolyzed sludge oil obtained from crackedgasoline sludge was mixed with 10% by weight of elementary sulfur andheated for 1 /2 hours at 290-30021. After this treatment, the sulfur wasfound to be completely reacted with the oil, forming a clear, viscousproduct of dark red color. ,This sulfurized material was found tocontain 8.42%.

sulfur by analysis and was perfectly soluble in a paraffinic mineraloil.

iilmen test data showed that a 10% blend of this sulfurized product in aPennsylvania lubri- It will be observed that the blend containing thesulfurized hydrolyzed sludge oil showed considerable load improvement,especially in the S. A. E. machine and in the Almen machine whenemployed in conjunction with chlorinated paraflin wax.

These sulfurized products may be employed in greases, motor oils,textile oils, industrial oils, ink oils, and other lubricating .andprocess compositions either alone or in conjunction with various typesof lubricating and light and heavy mineral or fatty oils with or withoutother addition agents such as dyes, pour inhibitors, V. I. improvers,soaps, antioxidants, oiliness agents, sludge dispersers, and the like.may be also added to Diesel fuel oils and similar compositions. Althoughsulfur is preferred, other elements of the sulfur group, such asselenium and tellurium may be employed in the preparation of thesecompositions.

I claim:

1. Process for the production of a sulfurized product comprisinghydrolyzing a naphtha acid sludge -to obtain an oily layer and anaqueous layer, recovering the oily layer, chlorine-ting said oily layerto a chlorine content of about 10-30% by weight, reacting saidchlorinated product with a reactive sulfur compound, and recovering theresulting sulfur-containing condensation product.

2. Process for the preparation of a blending agent for a minerallubricating oil to impart to the composite extreme pressure lubricatingcharacteristics which comprises hydrolyzing cracked naphtha acid sludgewith water at an elevated temperature, separating the aqueous layer thusformed, treating the residual oil material with I propane, settling,separating the thug; clarified eating oil of 40 vis. Saybolt at 210 F.was capable of carrying a full load of 15 weights gradual loading and5-7 weights shock loading upon this machine. The blend had a flash pointof 355 F.

Example III .-A sample of sulfurized base prepared in a manner similarto that described under Example I was blended in 10% concentration in amineral gear oil having a viscosity of 90 secs. Saybolt at 210 F. Ablend containing 10% of this base' and 8% chlorinated paraflln wax of40% chlorine content was also prepared and compared with a blend of thegear oil con taining only 8% chlorinated wax:

oil, heating said clarified oil to remove propane, distilling theresultant oil, chlorinating the distiliate material to a chlorinecontent of 10 to 30% by weight, reacting said chlorinated product with areactive sulfur compound, and recovering the resultant sulfur-containingcondensation product.

3. Process according to claim 2 in which the reactive sulfur compound issodium n-butyl mercaptide.

4. Process according to claim 2 in which the reactive sulfur compound issodium polysulflde.

5. Process according to claim 2 in which the reactive sulfur compound issodium hydrosulflde.

6. Process for the preparation of a blending agent for a minerallubricating oil to impart to the composite extreme pressure lubricatingchar- BRADSHAW F. ARMENDT.

They

